Abstract: A remote keyless entry (RKE) transponder has a programmable selective wake-up filter for determining whether the RKE transponder should wake-up to process a received signal. The wake-up filter correlates the timing of an input signal's carrier amplitude on and off time periods to a predefined programmable time period profile for a desired signal which has a certain carrier on time (time period on) and a certain carrier off time (time period off) arranged into a coded “header.” When a received signal matches the predefined time period profile, then the RKE transponder will wake-up to process the incoming signal data. The predefined time period profile may be programmable and may be stored in a header configuration register. Each RKE transponder has unique predefined time period on and time period off profiles.

Abstract: A remote keyless entry (RKE) transponder has a programmable selective wake-up filter for determining whether the RKE transponder should wake-up to process a received signal. The wake-up filter correlates the timing of an input signal's carrier amplitude on and off time periods to a predefined programmable time period profile for a desired signal which has a certain carrier on time (time period on) and a certain carrier off time (time period off) arranged into a coded “header.” When a received signal matches the predefined time period profile, then the RKE transponder will wake-up to process the incoming signal data. The predefined time period profile may be programmable and may be stored in a header configuration register. Each RKE transponder has unique predefined time period on and time period off profiles.

Abstract: A multi-channel remote keyless entry (RKE) transponder having dynamically re-configurable input channel selection, channel disable, settable sensitivity for each channel, wake-up filter timing parameters, automatic gain control hold, internal tuning capacitor selection for each channel's antenna, minimum modulation depth requirement for input signal and bi-directional talk-back. Programmable minimum modulation depth requirement reduces false wake-up of the RKE transponder. An antenna for each channel of the RKE transponder may be tuned with internal tuning capacitors for improved range and receiver sensitivity. The internal tuning capacitor parameters may be stored in a configuration register. Gain of the channel may be fixed while the antenna is tuned. The antennas may be de-queued for talk-back to a base station for low frequency bi-directional communications. An external control device may dynamically read from and write to the configuration registers via a serial communications interface.

Abstract: A remote keyless entry (RKE) transponder has a noise alarm timer having a time interval used for determining whether a received signal meets a predefined condition within a time interval. If the received signal meets the predefined condition within the time interval, the noise alarm timer is disabled and the RKE transponder circuits are enabled so that normal operation in processing the desired signal commences. If the received signal does not meet the predefined condition within the time interval the noise alarm timer issues an alert signal, whereby appropriate action may be taken such as adjusting the channel input sensitivity, disabling a channel, or placing the RKE transponder into a sleep mode in order to reduce the power consumption caused by undesired input signals. A smart wake-up filter determines whether or not the input signal meets the predefined condition within the time interval.

Abstract: A multi-channel remote keyless entry (RKE) transponder having dynamically re-configurable input channel selection, channel disable, settable sensitivity for each channel, wake-up filter timing parameters, automatic gain control hold, internal tuning capacitor selection for each channel's antenna, minimum modulation depth requirement for input signal and bi-directional talk-back. Programmable minimum modulation depth requirement reduces false wake-up of the RKE transponder. An antenna for each channel of the RKE transponder may be tuned with internal tuning capacitors for improved range and receiver sensitivity. The internal tuning capacitor parameters may be stored in a configuration register. Gain of the channel may be fixed while the antenna is tuned. The antennas may be de-queued for talk-back to a base station for low frequency bi-directional communications. An external control device may dynamically read from and write to the configuration registers via a serial communications interface.

Abstract: A remote keyless entry (RKE) transponder has a noise alarm timer having a time interval used for determining whether a received signal meets a predefined condition within a time interval. If the received signal meets the predefined condition within the time interval, the noise alarm timer is disabled and the RKE transponder circuits are enabled so that normal operation in processing the desired signal commences. If the received signal does not meet the predefined condition within the time interval the noise alarm timer issues an alert signal, whereby appropriate action may be taken such as adjusting the channel input sensitivity, disabling a channel, or placing the RKE transponder into a sleep mode in order to reduce the power consumption caused by undesired input signals. A smart wake-up filter determines whether or not the input signal meets the predefined condition within the time interval.

Abstract: A bidirectional remote keyless entry (RKE) transponder comprises an analog front-end (AFE) having a programmable wake-up filter that predefines the waveform timing of the desired input signal, minimum modulation depth requirement of input signal, and independently controllable channel gain reduction of each of its three channels, X, Y, and Z. The wake-up filter parameters are the length of high and low durations of wake-up pulses that may be programmed in a configuration register. The wake-up filter allows the AFE to output demodulated data if the input signal meets its wake-up filter requirement, but does not output the demodulated data otherwise. The AFE output pin is typically connected to an external device for control, such as a microcontroller (MCU). The external device typically stays in low current sleep (or standby) mode when the AFE has no output and switches to high current wake-up (or active) mode when the AFE has output.

Abstract: A remote keyless entry (RKE) transponder has a programmable selective wake-up filter for determining whether the RKE transponder should wake-up to process a received signal. The wake-up filter correlates the timing of an input signal's carrier amplitude on and off time periods to a predefined programmable time period profile for a desired signal which has a certain carrier on time (time period on) and a certain carrier off time (time period off) arranged into a coded “header.” When a received signal matches the predefined time period profile, then the RKE transponder will wake-up to process the incoming signal data. The predefined time period profile may be programmable and may be stored in a header configuration register. Each RKE transponder has unique predefined time period on and time period off profiles.